During Russia's invasion of Ukraine in February 2022, Telegram became an essential social media platform for Kremlin-sponsored propaganda dissemination. Over time, Anti-Kremlin Russian opposition channels have also emerged as a prominent voice of dissent against the state-sponsored propaganda. This study examines the dynamics of Anti-Kremlin content on Telegram over seven phases of the invasion, inspired by the concept of breach in narrative theory. A data-driven, computational analysis of emerging topics revealed the Russian economy, combat updates, international politics, and Russian domestic affairs, among others. Using a common set of statistical contrasts by phases of the invasion, a longitudinal analysis of topic prevalence allowed us to examine associations with documented offline events and viewer reactions, suggesting an adaptive breach-oriented communications strategy that maintained viewer interest. Viewer approval of those events that threaten Kremlin control suggests that Telegram levels the online playing field for the opposition, surprising given the Kremlin's suppression of free speech offline.